The invention relates to a gas bag restraint device for restraining an occupant of a vehicle.
A gas bag restraint device known from DE 197 49 914 A1 has a so-called annular gas bag, a so-called guide sleeve being arranged in the center of the gas bag module. The gas bag has a gas bag wall, said wall having a front wall with respect to the inflated state which faces the occupant who is to be restrained and which is the part of the gas bag which is moved most forward towards the occupant. The front wall comprises a ring shaped outer portion, which is to be contacted by the occupant, and a center section with a depression. The center section is surrounded by the ring shaped outer portion. A guide sleeve is firmly connected on the rear face with the gas bag module base and is firmly connected on the front face with the module covering. On opening of the module covering, a central section of the module covering remains. Also a fastening device with a separate nut and a cover which makes the nut invisible externally, is shown.
The invention provides a gas bag restraint device in which the fastening device is constructed more simply than. in the prior art, requires less space and the construction of the module covering can be designed so as to be less complicated. The gas bag restraint device according to the present invention comprises a gas bag module, which has a gas generator and a gas bag with a gas bag wall. The gas bag wall has a front wall facing the occupant, which front wall has a center section with a depression, in relation to an inflated state of the gas bag, so that an annular gas bag chamber surrounding the depression is formed. The device further comprises a module covering which on inflation of the gas bag opens an outlet opening, and a fastening device. for the center section, with which the center section is prevented from a free movement, preferably from any movement, out of the gas bag module even in the inflated state of the gas bag, so that the depression is formed. The fastening device comprises a reinforcement insert integrated into the module covering and fastened to the gas bag module.
The reinforcement insert, as stated, is integrated into the module covering by having been placed into the foaming or injection mold during the foaming or injection-molding of the module covering. The module covering therefore remains in the region of the center section on opening, and only the adjoining part folds outwards in order to open the outlet opening. Problems in connecting the fastening device to the module covering do not occur.
According to the preferred embodiment, the reinforcement insert is a metal sheet.
Holding pieces, such as threaded bolts, sheet metal tongues, rivet bolts or sections of a bayonet closure for example can project from the sheet metal insert, which protrude from the module covering and via which the fastening device is arrested on the module. The threaded bolts are, for example, bolted, the sheet metal tongues are bent over, the rivet bolts are tumble-riveted, and the bayonet closure is closed, in order to arrest the module covering together with the center section permanently on the module.
The arresting takes place for example immediately on the gas generator, more precisely on the gas generator housing. Here, the center section is gripped between the front end wall of the gas generator and the module covering.
According to another embodiment, the reinforcement insert is fastened to a cup-shaped diffusor which is turned over the gas generator, or to a component surrounding the gas generator, e.g. a bracket. Here, the center section is gripped between the front end wall of the diffusor and the module covering.